The storage sidings are almost complete...
In this picture, the track beds are fixed but the track itself is not. The design for the storage sidings was finalised at the start of this week after some playing around in XTrkCAD. Five sidings is not that many but I think I will probably have about five trains. There will also be some sidings topside that can be used to park trains if I end up with more.
Concerning the track itself, I have still to decide whether to use my existing Hornby sectional track. The reason why I wouldn't is because it is very grimy and contact is sporadic at best. I tried cleaning all the track a few months ago, but the grime has returned already. For the hidden storage tracks I don't want to be worrying whether the rails are clean enough; trains have to enter and leave the sidings smoothly and under their own power. So I might have to invest in new trackwork. It will probably be flexible track just because the straight lengths and curve radii are not exactly standard according to Hornby geometry.
The next job is to test the running height along the sides of the layout. I want to do that over the weekend if there's time.